Governing mechanism for turbines.



R. H. RICE. GOVERNING MECHANISM r011 TURBINES.

APPLICATION FILED MAR.6, 1908.

Patented Sept. 6, 1910.

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"Wire" earns PATENT crazier.

Brennan H. men, or LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRICoMPANY, A CORPORATION OF NEW YORK.

GOVERNING MECHANISM FOR TURBINES.

To all whom it may concern:

Be it known that I, RICHARD H. RICE, a citizen of the United States,residing at Lynn, county of Essex, State of Massachusetts, have inventedcertain new and useful improvements in Governing l\[echanism forTurbines, of which the following is a specitication.

The present invention relates to governing mechanisms for that type ofturbine wherein oppositely rotating wheels are provided, each mounted onand driving a shaft which ismechanically independent of the other, the'said shafts driving separate loads, such for example, as the rotors ofelectric generators. v

With such an arrangement, it may l1appen that the load conditions willbe such as to prevent the bucket wheels from running at theirdesignedspeeds. For example, supposetheload on the bucket wheel thatfirst receives steam is increased, the said wheel will slow down andmore steam will be ad-' mitted by the controlling valve or valves whilethe other wheel owing to the additional supply of steam will abnormallyincrease in speed, resulting in excessive voltageof the generatordriventhereby, and possibly in wrecking the wheel due toabnormal"centrifugalstrains. On the other hand, the load on the secondbucket wheel inay be greatly decreased or entirely removed and if thesteam supply is maintained constant, the voltage of the generator driventhereby will in the first in stance be increased above normal and in thesecond instance the wheel may be wrecked due to excessive centrifugal stam.

My invention has for its object to provide an improved governingmechanism for turbines having independently movable wheels, each drivingits own load, which is so arranged that an increase in speed of eitherwheel above the predetermined limit will decrease. the steam supplied tothe turbine as a whole, thereby preventing. in'ury to either of thebucket wheels. In other words the object of my invention is to providean im: proved governing mechanism for a turbine ofthc type describedwherein a single speed governor for controlling the mechanism isnormally driven by both wheels but which is driven by the wheel havingthe greater speed to the exclusion of the other when the conditionsbecome abnormal.

Specification of Letters Patent.

Annlicaticn filed March 6, 1908.

PateutedSept. 6, 1910.

Serial No. 419,442.

In the accompanying drawing illustrating one of the embodiments of myinvention, Figure 1 shows a turbine having oppositely rotating bucketwluwls'equipped with my improved governing mechanism; Fig. 2 is asectional view taken on line 2-2 of Fig. 1, looking downward; Fig. 3 isa detail view showing intermediate buckets between the wheel buckets:Fig. 4 is a detail view showing oppositely rotating bucket wheels placedclose together so that the steam passes directly from one to the other;and Fig .5 is a detail view of the valve operating in echanism.

'1 indicates the bedplate and mounted thereon is a turbine casing 2having an exhaustv chamber 3 which communicatesby the conduit 1- with acondenser or other exhaust. The turbine is provided with two. oppositelyrotating bucket wheels'5 and 6. The wheel 5 is mounted on a shaft 7 andthe wheel (3 on the shaft 8. Each of these shafts is pro- 'vided withits own bearings and the shaft 7 drives the rotor of the generator 9 andshaft 8 drives the rotor of the generator 10. Steam is admitted to theturbine from the valve chest 11, through one, two or more nozzles 12.These nozzles are controlled by valves and said nozzles direct steamagainst the buckets of wheel 5. from this wheel passes through thepassages between the intermediate buckets ll and thence through thepassages'in the .wheel 6 and acts on the buckets.

The right hand main shaft 7 is provided.

with a worm 15 that meshes with a worm wheel 16 mounted on the lower endof the vertical shaft 17. Mounted on this shaft in line with the valvechest is a worm 18 which meshes with a worm wheel 19 on thevalveactuating shaft 20. This shaft drives cams which in turn act onforkcdmembers for opening and closing the valves successively as theload conditions change. The shall and cams are movable in an axialdirection by the speed governor as the load changes.

The left hand main shaft 8 is provided with a worm 25 which meshes witha worm wheel 26 carried by the upright low speed shaft. .27. On theupper end of this shaft is a disk 28 that contains one, two or morerecesses having inclined walls 29 as shown in F ig. 2. Located in therecesses are rollers 30 that are spring pressed in one direction andwhich' are so arranged that when the The steam issuing disk 28 isrotated in a clockwise direction, the rollers will engage the innersurface or bore of the ring 31, but When the ring tends -to travelfaster than the shaft 27 "and disk 28, the rollers will permit the partsto slip. In other words, under certainconditions, the ring can overrunthe disk. On the periphery of the rin are gear teeth which I mesh Withthose of the intermediate gear .ing elements. '35 is the surroundingring the bore of which cooperates with the rollers and its periphery isprovided with gear teeth that mesh with the teeth of'the gear .may be.

32. The intermediate gear 82 is mounted on a short vertical shaft 36that is supported by a bearing in the frame 37, the latter being carriedby the turbine casing or other suitable support. Mounted on the shaft 36and abovethe frame is a spur gear 38 meshing with a gear 39 mounted onthe shaft of governor 10, said shaft being located in a bearing in theframe 37. The governor may be of any suitable construe: tion. In thepresent case the movable element is connected by rod 41 with thegovernor lever 4-2. The lever is pivoted at one side. of the governorand on the free end is connected by the rod 43 with one arm of the bellcrank lever 44, which shifts the cams carrying shaft 20 back and forthin an axial direction as the load of the turbine varies. V

The action of my improved governing mechanism is as follows: Assumingthat the .the gear 32 at a certain constant speed.

The shaft 36 drives the governor 40, and if the speed of the main shafts7 and 8 increase.

or decrease simultaneously the governor will act to decrease or increasethe amount of steam admitted to theturbine as the case On the otherhand, assuming that the load on the right hand generator 9 in creases,that on the left hand generator remaining constant or even decreasing,this will cause a decrease in speed of the bucket wheelfi and anadditional steam supply accompanied by an increase in speed of thebucket wheel 6 and its generator. Any increase in speed of the shaft 8is accompanied by a corresponding increase in speed of the upright shaft27 and the disk driven thereby. Since the arrangement of the recessesand the rollers therein is such as to form a clutch which grips whenmoved in one direction but not in the other. it follows that since thespeed of the shaft 27 is higher than that of the shaft 17, the gear 31will drive the gear .32 at a. speed slightly in excess of that, due tothe rotation of the shaft 17. Since the rollers form a clutch that actsone way only, the shaft 27 .will assume control and do the driving whilethe clutch between the low speed shaft 17 and the gear 32 will overrun.-

This means that the governor will act on the valve mechanism in a mannerto decrease the supply of the motive fluid to the turbine. On the otherhand, if the bucket wheel 6 decreases its speed due to load and thewheel 5 increases its speed, the reverse of theabove will take place andthe driving of the governor will be done by the gear 35, the clutch;rollers in the gear 31 automatically releasing gear to over- Inaccordance with the provisions of the 95 ciple of operation of myinvention together patent statutes, I have described the prin- In otherwords the bucket wheel 5 willwith the apparatus which I now consider torepresent the best embodiment thereof; but. I desire to have itunderstood that the apparatus-shown is only illustrative, and that theinvention can be carried out by other means."

What I claim as new and desire to secure by Letters Patent oft-he'United States, is,- 1. In combination, turbine elements, regulatingmeans controlling the admission of emotive fluid thereto," shafts forsaid elements, gearing between said shafts including an intermediategear, a single speed-responsive device'driven by said intermediate gearwhich modifies the position of the regulating means, and automaticclutches controlling the transmission of motion from said shafts to theintermediate gear so that said device can be driven normally by all ofthe elements and under abnormal conditions by the element having thegreatest speed to the exclusion of the others.

' 2. In combination, turbine elements," a regulator controlling thesupply of, elastic fluid thereto, a' governor for actuating theregulator which is driven by the turbine elements, and means including aclutch mechanism for permitting one of the ele-' ments to drive thegovernor to theex cliision of the remainder under certain condi tions.

3. In combination, turbine elements, a regulator controlling thesupplyof elastic -fiuid thereto, a governor for actuating the regulator whichis driven by the turbine elements, and means includin r a clutchmechanism interposed between tilie elements and the governor whichpermit the element rotating at the highest speed to assume control tothe exclusion of the remainder.

4. In combination, turbine elements, separate shafts therefor, aregulator controlling the supply of motive fluid to said elements, aspeed governor, a connection between each element and the governorwhereby the elements normally cooperate to drive the governor, and aclutch device in each connection which permits the one having the lesserspeed to run idly while the other drives the governor.

5. In combination, turbine elements, separate shafts therefor, aregulator controlling the supply of motive fluid to said elements, aspeed governor, a driving connection be tween each element and thegovernor, gearing in said connections, and clutches in said gearingwhich slip in one direction and not 1n the other.

6. In combination, turbine elements, separate shafts therefor, aregulator controlling the supply of motive fluid to said elements, aspeed governor, lowspeed shafts driven by the main shafts, gearingbetween the lowspeed shafts and the governor for driving the latter, andclutches for transmitting power from the low-speed shafts to thegovernor which normally are in o eration and which permit the low-speedsha t having the greatest speed to drive the governor to the exclusionof the others.

7. In combination, turbine elements, separate shafts therefor, a'speedgovernor driven by said shafts, and clutches which normally transmitpower from the shafts to the governor, one of which becomes inactivewhen the normal speed relation between the shafts is disturbed.

8. In combination, turbine elements, separate shafts therefor, is commonto said elements, gearing for driving the governor at a s eed less thanthat of the shafts, and clutches interposed between the shafts and thegovernor which act in one i'ay only.

a speed governor that In witness whereof, I have hereunto set my handthis second day of March, 1908.

' RICHARD H. RICE;

Witnesses JOHN A. MCMANUS, Jr., HENRY O. WESTENDARP.

